The present invention provides a high-performance phosphorous-containing hardener with excellent flame retardant and heat resistant characteristics, as well as a low dielectric constant with the following formula disclosed (see FIGS. 1A and 1B). When the phosphorous-containing hardener is formulated with compositions for laminate, it can pass the UL-94V0 flame retardant test, with the value of the dielectric constant being 4.0 (1 GHz), and does not experience delamination with 10 minutes of dipping in a 288° C. soldering test after two hours of the pressure cooking test.
This phosphorous-containing hardener may be used as a raw material for epoxy resin or cynate resin or as a hardener for epoxy resin. It can be used in a variety of applications, including, for example, insulating materials for highly reliable electronic components, such as EMC, PCB substrates, laminate and insulating plates that require excellent flame-retardant characteristics and thermal stability, adhesives, coating agents, and paint.
wherein n+y+m=2.5 to 3, the average value of n is 1 to 2.8, y is 0.1 to 1, m is 0.1 to 1 and x is 0 to 5.    (note: n or y or m group has four ortho-reactive contacts relative to the phenolic hydroxyl group on bisphenol A)